Method for controlling tree growth

Abstract

Tree growth is suppressed by placing an implant below the bark layer of the tree at each of a plurality of sites spaced around the circumference of the trunk of the tree, each implant containing a unit dose of active ingredient selected from flurprimidol, paclobutrazol, and uniconazole.

I claim: 
     
       1. A method for delivering to the terminal shoots of a tree a growth supressing amount of flurprimidol, which comprises placing an implant below the bark layer of the tree at each of a plurality of sites spaced around the circumference of the trunk of the tree, each implant containing a unit dose of flurprimidol. 
     
     
       2. The method of claim 1 wherein the implant is of suitable size and shape so that it can be inserted into a 3/8 inch diameter or smaller hole. 
     
     
       3. The method of claim 1 wherein the implant contains a 0.1 to 2.0 g dose of the active ingredient. 
     
     
       4. The method of claim 1 wherein the implant contains a 1.0 g dose of the active ingredient. 
     
     
       5. The method of claim 1 wherein the implant comprises 25 to 100% by weight of the active ingredient. 
     
     
       6. The method of claim 1 wherein the unit dose implants are tablets. 
     
     
       7. The method of claim 6 wherein the tablets include pre-gelatinized starch. 
     
     
       8. The method of claim 1 wherein the application rate is in the range from 0.01 to 4.0 g/in dbh. 
     
     
       9. The method of claim 1 wherein the application rate is in the range from 0.01 to 1.5 g/in dbh.